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It is well known that the vertical vibrations of lightweight timber floors would cause discomfort to the occupants. As a new kind of flooring system, the metal-plate-connected timber truss joist floors were developed due to their larger spans and easier crossing of pipes and cables after sawn timber and I-joist floors. In this paper, the vibration modes and transfer functions of sixteen metal-plate-connected timber truss joist floors over a nominal span of 6 m were determined experimentally to measure the changes in vibration frequencies and transmissions obtained after the installation of strongbacks and strappings. The results showed that the fundamental natural frequencies of the metal-plate-connected timber truss joist floors at a 400 mm joist spacing were about 15 Hz, while the frequencies of the floors at a 600 mm joist spacing were about 12.5 Hz. The bracing elements of the strongbacks and strappings mainly enhanced the system stiffness in the across-joist direction of the flooring system, but they did not govern the fundamental natural frequencies of the floors and just changed the spacing of adjacent natural frequencies. The bracing elements as secondary elements of the floors also altered the vibration transmission paths in the across-joist direction. The frequencies where the stronger vibration transfers happened in the direction perpendicular to floor joists were generally above 15 Hz. Proper installation measurements of bracing elements in practical control need to be taken to alleviate the vibration response intensity at the targeted locations and frequencies.

Background Atrial fibrillation (AF) has the close relation to thyroid dysfunction and these two diseases lead to poor cardiovascular outcomes. But the prognostic value of thyroid diseases in AF remains unclear. We aimed to determine whether history of thyroid diseases is associated with risk of in-hospital cardiovascular outcomes in AF. Methods Based on the data from the CCC-AF (Improving Care for Cardiovascular Diseases in China-Atrial Fibrillation) project, 31,486 inpatients with a definitive diagnosis of AF and record of history of thyroid diseases were included. Logistic regression analysis was performed to investigate the relationship between history of thyroid diseases and risk of in-hospital major adverse cardiovascular events (MACE) in AF. Results Among AF patients, 503 (1.6%) had a history of hypothyroidism, 642 (2.0%) had a history of hyperthyroidism and 30,341 (96.4%) had no thyroid dysfunction. During this hospitalization, 5146 (16.3%) AF patients suffered from MACE. The incidence was 13.1% in hypothyroidism, 16.3% in euthyroidism and 19.0% in hyperthyroidism, in which there was a significant difference among three groups (p = 0.028). Multivariable logistic regression analysis revealed that history of hypothyroidism decreased but history of hyperthyroidism increased the risk of in-hospital MACE in AF patients (adjusted odds ratio [OR] = 0.603; 95% confidence interval [CI], 0.449–0.811; p = 0.001 versus adjusted OR = 1.327; 95% CI, 1.060–1.661; p = 0.013). Conclusion History of hypothyroidism was an independent protective factor, whereas history of hyperthyroidism was an independent risk factor for in-hospital cardiovascular outcomes in AF. Our study indicated that hyperthyroidism should be treated aggressively in order to improve the prognosis of AF.

A dual-channel two-dimensional (2D) reflection grating filter operating around the 1.55 µm wavelength region is demonstrated, exhibiting dual-channel reflection peaks at 1.492 µm and 1.647 µm. The sidebands intrinsic to this kind of grating are suppressed by appropriately designed antireflective thin films, and this can be proved by equivalent medium theory. Using the modal analysis method, the excitation modes of the dual-channel reflection peaks are determined to be the TM0 (1.490 µm) and TE0 (1.638 µm) modes. The estimated relative errors in the wavelength determination of these modes are less than 1%. This is found to be in accord with analyses of the reflectivity spectra and electromagnetic fields. The dual-channel reflection peaks are sensitive to the background refractive index and may be useful in biosensing applications.

The photonic spin Hall effect metasurfaces utilizing broadband highefficiency half-wave plate were proposed, which can generate broadband high- intensity left and right circular polarized light that could be applied in chiroptical spectroscopy.

The dual-channel two-dimensional reflection grating filter is demonstrated. The design of anti-reflective thin films suppresses the sidebands and the corresponding excitation modes of dual-channel reflection peaks are determined.

Broadband multilayer dielectric gratings (MDGs) with rectangular HfO2 grating profile were realized for the first time using a novel fabrication process that combines laser interference lithography, nanoimprint, atomic layer deposition and reactive ion-beam etching. The laser-induced damage initiating at the grating ridge was mitigated for two reasons. First, the rectangular grating profile exhibits the minimum electric-field intensity (EFI) enhancement inside the grating pillar compared to other trapezoidal profiles. Second, our etching process did not create nano-absorbing defects at the edge of the HfO2 grating where the peak EFI locates, which is unavoidable in traditional fabrication process. The fabricated MDGs showed a high laser induced damage threshold of 0.59J/cm2 for a Ti-sapphire laser with pulse width of 40 fs and an excellent broadband diffraction spectrum with 95% efficiency over 150 nm in TE polarization.

Through the introduction of a broadband ( ∼ 1 µ m ) high-efficiency (average above 90%) half-wave plate in the near-infrared (NIR) region, reflective Pancharatnam–Berry metasurfaces that can generate high-intensity (above 90%) left-circular polarization (LCP) and right-circular polarization (RCP) light for broadband ( ∼ 900 n m ) are designed. It provides a method to generate broadband high-efficiency circularly polarized (CP) light, which is a rare complex process in traditional chiroptical spectroscopy. To further show the broadband high-efficiency function of the meta-atom, a broadband high-efficiency reflective vortex beam generator based on metasurfaces is designed for RCP light in the NIR region. Moreover, with the appropriate arrangement, the metasurfaces are able to focus the vortex beam into a point to increase the intensity of the generated vortex beam.

Optical metasurfaces, two-dimensional counterparts of the metamaterials, are comprised of arrays of subwavelength engineered inclusions that can locally modify optical field and light–matter interactions, thus offering fascinating possibilities to realize unprecedented photonic phenomena. Here, a micro-structured optical coating or a hybrid multilayer structure is proposed. It is easy to achieve phase control over 2π by changing the geometric parameter, which is used to design gradient metasurface exhibiting anomalous reflection for linearly polarized light (1μm). By arranging the arrays elaborately, the efficiency can reach as high as 93.6%. Besides, reflective metalens taking advantage of the Pancharatnam-Berry phase is demonstrated. The electric field distribution unambiguously indicates that the metalens can focus the plane wave with high efficiency (60.3%). Such structure may find various potential applications in nanophotonics because of their high freedom to design metasurfaces.

IntroductionAcute coronary syndrome (ACS) is one of the leading causes of death. Depression and/or anxiety after ACS is common. Studies from developed countries have reported that the occurrence of anxiety or depression after ACS might increase the risk of cardiovascular events and mortality. However, the results varied, and are limited in developing countries. Therefore, well designed large-scale real-world study is needed to make further clarification. The main objective of this study is to evaluate whether depression or anxiety could affect the prognosis of patients with percutaneous coronary intervention (PCI) post-ACS.Method and analysisThe study is a prospective, multicentre, cohort study, which will be performed at 12 large hospitals in northwest China and led by the First Affiliated Hospital of Xi'an Jiaotong University. A total of 5000 patients with PCI post-ACS will be enrolled and followed up for 2 years. Their depression and anxiety status will be evaluated with the Patient Health Questionnaire-9 or Generalised Anxiety Disorder-7 Assessment scales during the follow-up. A Cox proportional hazard model will be used to determine if depression/anxiety after PCI increase the risk of cardiovascular events. The impact of antidepression or antianxiety treatment on the cardiac prognosis will be explored as well among the patients with ACS who received the treatment after PCI.Ethics and disseminationThis study has been approved by the ethics committee of the First Affiliated Hospital of Xi'an Jiaotong University (approval number: XJTU1AF2016LSL-036). The results will be published in research articles or conference papers.Trial registration numberNCT03057691.